The primary objective of the TIPP study is to determine if prophylactic administration of low dose indomethacin to infants with birth weights of 500-999 grams improves survival without neurosensory impairments to a corrected age of 18 months. Preliminary evidence suggests that prophylactic low dose indomethacin reduces both the frequency and severity of intra- and periventricular hemorrhages and the frequency of symptomatic PDA. However, many physicians are reluctant to implement prophylactic indomethacin for all tiny babies due to concerns about the lack of data on long-term outcomes. It is possible that adverse effects of indomethacin such as reduced cerebral perfusion have not been detected in previous trials. Despite recent improvements in the overall outcome of extremely low birth weight infants, extreme prematurity remains a serious risk factor for early death or life long disability. Clearly, reducing morbidity rates among very low birth weight infants is important for affected patients and their families as well as for society at large. If the apparent benefits of early indomethacin translate into tangible advantages at long-term follow-up, clinicians may overcome their current objections to indomethacin prophylaxis. If, on the other hand, the risk/benefit ratio of early indomethacin is not favorable at 18 months corrected age, exposure of all tiny infants to this potent drug will be discouraged.